A method of inducing immediate asthmatic response (IAR) by inhalation of an allergen in a patient with atopic asthma has been employed as an experimental model for respiratory distress in bronchial asthma. Namely, when a patient with atopic asthma inhales an allergen, then the patient has an asthmatic response (broncho-constriction) after about 20 minutes, and further 2 hours thereafter, the symptom returns to the original condition. Then, keeping on observation of the patient who had immediate asthmatic response, it has been confirmed that about half of the patients who have immediate asthmatic response showed again a bronchoconstriction 6 to 10 hours thereafter, and it was named as late asthmatic response (LAR) (cf., Booji-Noord, H, et al., J. Allergy Clin. Immunol., 48, 344-354, 1971). In late asthmatic response, the bronchial obstruction lasts for a long period, and pulmonary overexpansion is accompanied thereto, but this response is strongly suppressed by corticosteroids. From this fact, the above bronchial asthma induced by an allergen has been recognized as an important clinical model for steroid-dependent respiratory distress of serious bronchial asthma. Immediate asthmatic response has been considered as type I allergy induced as a result of a mast cell activation by IgE antibody, while late asthmatic response has been considered as T lymphocyte- and eosinophilic-induced allergic responses (eosinophilic inflammation). It has been clarified that these immediate asthmatic response and late asthmatic response are also induced in the allergic rhinitis or atopic dermatitides (cf., OKUDAIRA Hirokazu, medicina 34, p. 200-203 (1997)). In addition, the bronchoalveolar eosinophilia during allergen-induced late asthmatic reactions has been reported in a patient with bronchial asthma (cf., De Monchy, J. G., et al., Am. Rev. Respir. Dis., 131, 373-376 (1985)). From the increase of eosinophils in the peripheral blood and sputum of many patients with bronchial asthma, massive infiltration by eosinophils in the pulmonary tissue of a patient who died by asthma, and the deposition of major basic protein (MBP) at bronchial wall and mucous plug of patients, which is a tissue toxic protein derived from eosinophils, certain product derived from eosinophils has been considered to play an important role in bronchial epithelium injury accompanying to late asthmatic response (cf., Filley, W. V., et al., Lancet. 2 (8288), 11-6 (1982)).
At present, the concept of developing bronchial asthma has been considered as a chronic inflammatory disease from a simple reversible bronchial spasm, and according to this change of the concept, a method for treatment thereof should also have been changed. US National Institute of Health National Heart Lung Blood Institute (NIH/NHLBI) and WHO announced a Global Initiative for Asthma (GINA) for controlling and preventing asthma in 1995, and it has been an international guidance for treatment of a patient with bronchial asthma. As mentioned above, until comparatively lately, bronchial asthma had been considered as type 1 allergy in which IgE antibody participates, and a medicament for treatment thereof had been developed based on a role of mast cell in the mechanism of pathogeny thereof. However, at present, as shown in the opinion of NIH/NHLBI, bronchial asthma is positioned to be an inflammatory disease at airway, and bronchial asthma is considered to be “chronic epithelium desquamative eosinophilic infiltrative bronchial infection” as inflammation of airway induced by inflammatory cells which are mainly eosinophils/T lymphocytes (cf., Miwa MISAWA, Folia Pharmacologica Japonica, 111, 193-194 (1998)). In the above-mentioned GINA, conventional methods in Europe and the United States for treatment of asthma have mainly been employed, and inhaled corticosteroids are used as a primary choice. According to this guide line, there is established a guide line for treatment of asthma having inhaled corticosteroids as basal medication in Japan (cf., under the editorship of Sohei MAKINO, Japanese Society of Allergology, Guide Line for treatment of Allergic diseases, p. 3-65, Life Science Medica (1995)).
Corticosteroids are considered to be the only remedy for serious bronchial asthma and atopic dermatitis, but they exhibit their potent effects as well as side effects such as hypertension, diabetes mellitus, obesity, immune suppression, cataracta, mental disorder, atrophy cutis, etc. Inhaled corticosteroids have been developed in order to reduce such systemic side effects of steroids, but it is difficult to prove that corticosteroids administered by inhalation do not circulate in entire body, and fears for inherent side effects of corticosteroids cannot be eradicated. Recently, side effects of inhaled corticosteroids have been reported in Europe and the United States, and FDA of the United States instructs to attach a warning as to the risk of side effects to inhalant corticosteroids for treatment of bronchial asthma and nasal inhalant corticosteroids for treatment of allergic rhinitis (Konig, P., Allergol. Int., 49, 1-6 (2000)).
As mentioned above, the infiltration by eosinophils into lesion plays an important role in the onset and exacerbation of late response of not only bronchial asthma but also of allergic dermatitis or rhinitis. However, by suppressing the infiltration and activation of eosinophils, only corticosteroids are specific remedies for treatment of allergic diseases, for example, bronchial asthma, and in the clinical field, it has been desired to develop an anti-inflammatory agent, which can take the place of corticosteroids, and have fewer side effects and also can be orally administered. For example, as a trial of developing an agent for suppressing eosinophilic inflammation, an antibody neutralizing interleukin-5 (anti-IL-5 neutralization antibody), which induces the proliferation-differentiation of eosinophilic precursor cell, extension of survival of mature eosinophils (cf., Garlisi, C. G., Pulm. Pharmacol. Ther., 12, 81-85 (1999)), a low molecular inhibitor of Very Late Antigen 4 (VLA-4), which is an adhesive factor being specific to eosinophil (cf., Haworth, D., et al., Br. J. Pharmacol., 126, 1751-1760 (1999)), a low molecular antagonist against CCR3, a receptor of eotaxin, which is a chemokine being specific to eosinophil and induces eosinophil migration (cf., Wells, T. N. C., et al., Inflammation Res., 48, 353-62, (1999)) have been studied, but they cannot take the place of corticosteroids yet.
On the other hand, L-threo-3-(3,4-dihydroxyphenyl)-N-[3-(4-fluorophenyl)propyl]serinepyrrolidinamide has been known to exhibit an inhibitory effect of eosinophil migration (cf., Sugasawa, T. and Morooka, S., Recent Advances in Cellular and Molecular Biology, 3, 223-227, Peeters Press, Leuven, Belgium (1992), Sugasawa, T. et al., J. Biol. Chem., 272, 21244-21252 (1997), WO 98/26065). The in vivo specific binding site of this L-threo-3-(3,4-dihydroxyphenyl)-N-[3-(4-fluorophenyl)propyl]serinepyrrolidinamide is a receptor-like membrane protein and referred to as SMBS protein (SMBP) (cf., Sugasawa, T. et al., J. Biol. Chem., 267, 21244-21252 (1997), WO 98/26065).
Therefore, if the eosinophil migration can be inhibited by binding to this SMBS protein, then it may be possible to treat allergic diseases such as asthma, etc.